Plants offer a promising solution in providing food to astronauts thousands of miles from Earth.

The plants would not only provide food and O2 for the humans, but also remove toxic carbon dioxide from the air inside their spacecraft and also help purify wastewater.

The need to generate oxygen and grow food in space inspired NASA to test indoor agriculture techniques including vertical farming and hydroponic system.

The Plants grow using nutrient film technique, a vertical hydroponic system.  A dense root mat that absorbs water, nutrients, and oxygen without using soil develop. A thin film of water continually flows through the tray underneath the roots, using 2-5% of the water required by plants grown outdoors.

The LED lights are used in vertical farms. In Fact, the mix of red and blue light for each plant species adjust. NASA design a green wheel hydroponic garden for growing plants.